1. Field of the Invention
This invention is generally concerned with compositions and methods of controlling animals, and more particularly, it is directed to a novel synergistic mixture of certain compounds for repelling animals and, in particular, dogs and cats.
2. Description of the Prior Art
For reasons of health and convenience it has frequently been found to be desirable to discourage animals from frequenting certain areas. For example, garbage receptacles become both an unpleasant chore to handle and a serious potential health hazard after being ravaged by domestic animals, such as dogs and cats, or by non-domestic animals, such as mice, rats, coyotes, wolves, or the like.
Chemical agents are commonly employed to discourage such animals from approaching those areas from which mankind finds it desirable to exclude them but, while there are many chemical compounds which would effectively repel ravaging animals, there are two restrictions which severely limit the number of chemicals actually available for use. The first restriction is toxicity: the compounds used must be substantially, and preferably completely, non-toxic to mammals since they will frequently be used in proximity to small children and household pets, and the probability of contact and ingestion is high. The second restriction lies with the organoleptic properties of the compound as relates to humans, especially its odor: if the agent is such that it is repulsive or even unpleasant to humans, then it will not be suitable for use in populated areas. Among the relatively few compounds which meet these strictures and are known to have at least some ability to repulse animals are undecanone-2 and 3-phenylpropenal.
Undecanone-2, commonly known as methyl nonyl ketone, is disclosed in U.S. Pat. No. 2,283,471 (Swaine) as being a useful insecticide, and its utility as an animal repellant is taught by Freeman in U.S. Pat. No. 3,474,176 and also by Paulson in Canadian Pat. No. 978,475. The compound has a low level of mammalian toxicity and is one of the active ingredients in many commercial animal repellant formulations.
3-Phenylpropenal (common names: cinnamaldehyde; .beta.-phenylacrolein) is widely used in the perfume industry and is known to exhibit biological activity. U.S. Pat. No. 2,465,854 (Dorman, et al.) teaches the use of both the aldehyde and its derivatives as insecticides. Lehner et al. reported in the Journal of Wildlife Management, 40 (1): 1976 pp 145-150, that the compound showed promise as an olfactory repellant for coyotes and dogs. The fact that this compound is widely used as a synthetic cinnamon flavor and odor additive is testimony to its organoleptic appeal to humans.